My 2.6 cabrio will crank over quickly but will not start except if i put neat petrol into trottle body .I have put on a new fuel pump and filter and there is loads of fuel at the fuel rail .when a spark plug is removed it is dry so no fuel being injected .spark seems as it should be.when car is started by giving it a drink of fuel it runs perfectly for as long as you keep it going .If it is stopped it will not start again.PLEASE HELP!!!